1. Field of the Invention
The present invention relates to a remote starting control apparatus and a starting control apparatus, and more specifically, to a remote starting control apparatus employed for a vehicle that has an immobilizer function, and to a starting control apparatus that also has an immobilizer function.
2. Description of the Related Art
Recently, the number of vehicles provided with antitheft functions, called immobilizer functions, has increased. As is shown in FIG. 19, providing an immobilizer function for the engine of a vehicle requires an ignition key 1 having a grip portion 2 that includes a chip 2, in which a specific code having a transmission function is stored, and a key cylinder 4; a transponder 5 that is attached to the key cylinder 4; an immobilizer unit 6 that serves as an antitheft device and in which a code unique to the vehicle is stored; and an engine controller 7 for controlling such functions as the starting of the engine.
When a driver inserts the ignition key 1 into the key cylinder 4 (or uses the ignition key 1 to rotate an ignition switch to either the ACC or the IG output position), a key insertion detection signal goes High, and upon receiving this signal, the immobilizer unit 6 transmits a start signal along a signal line L1 to the transponder 5.
Upon receiving the start signal, the transponder 5 employs a wireless connection to communicate with the chip 3 of the ignition key 1 inserted into the key cylinder 4, and obtains the specific code stored in the chip 3. Then, the transponder 5 transmits the specific code, together with a clock signal, along a signal line L2 to the immobilizer unit 6.
The immobilizer unit 6 then determines whether the specific code received from the transponder 5 matches a previously stored unique vehicle code. When these codes match, the immobilizer unit 6 assumes that the driver who inserted the ignition key 1 into the key cylinder 4 is an authorized driver, and transmits an engine start permission signal to the engine controller 7.
When the engine controller 7 receives the start permission signal, and thereafter receives the start signal from the key cylinder 4, it performs engine control processes, such as a fuel supply process and an ignition time setting process. However, when the engine controller 7 receives the start signal, but does not receive the start permission signal, it disregards the start signal and takes no further action.
As is described above, the engine can not be started unless the code stored in the chip 3 of the ignition key 1 is the unique vehicle code. Therefore, the direct connection of an illegal ignition key or ignition switch disables the engine startup process and prevents the theft of the vehicle.
Remote start control apparatuses for starting machinery, such as engines, are also in practical use today. As is shown in FIG. 20, when a remote start control apparatus 18 receives an engine start instruction signal from a portable transmitter 19 carried by a driver, the remote start control apparatus 18 outputs to an engine controller 17, along an ignition switch signal line L3, pseudo signals for an ACC signal, an IG signal and a start signal that are output when an authorized ignition key 11 is used to turn a switch to a starter output position.
As a result, an engine can be started when only an engine start instruction signal is transmitted by the portable transmitter 19, and in this case, the ignition key 11 need not be inserted into the key cylinder 14 and turned.
However, when a vehicle having the immobilizer function is to be additionally equipped with a remote start control apparatus 18, the unique vehicle code stored in the immobilizer unit 6 must be matched, i.e., the authorized ignition key 1 must be inserted into the key cylinder 4. Therefore, even when the pseudo signals for the ACC signal, the IG signal and the starter signal are transmitted to the engine controller 7, the engine can not be started.
To resolve this problem, an alternate technique is disclosed in JP-A-10-176642 (conventional example 1). According to this technique, a unique vehicle code is stored in a remote start control apparatus, and when the remote start control apparatus receives and transmits an engine start instruction, it also transmits the unique vehicle code to an immobilizer unit. Thereafter, the immobilizer unit transmits a start permission signal to an engine controller.
However, with the technique disclosed in conventional example 1, if a thief were to break into a vehicle and steal the remote start control apparatus, the thief could analyze the data stored in the apparatus and identify the unique vehicle code. Then, were the unique vehicle code obtained in this manner, the ignition key (i.e., the authorized ignition key) in which the code is stored could be copied, and stealing the vehicle would be easy.